Final answer:
- In Brilliant Green Lactose Bile (BGLB), the component that inhibits non-coliform growth is brilliant green dye. This dye is selective for coliforms and inhibits the growth of other bacteria. The component that allows for the differentiation of coliform from other members of the enterobacteriaceae group is lactose. Coliforms ferment lactose, causing a color change in the medium from red to yellow.
- Coliforms are gram-negative rod bacteria that ferment lactose. They are commonly found in the intestines of warm-blooded animals, including humans. Coliforms are used as indicators of fecal contamination in water, as their presence suggests the presence of other pathogenic organisms that may be harmful to human health.
- If the lab technician mistakenly added glucose instead of lactose in the medium, the results and interpretation would differ. Glucose is not a differentiating substrate for coliforms, so the color change from red to yellow would not occur.
Step-by-step explanation:
**1. Brilliant Green Lactose Bile (BGLB) is both a selective and differential medium used in the Multiple Tube Fermentation Method for Total Coliform Determination. In BGLB, the bile salts and brilliant green components of the medium inhibit the growth of non-coliform bacteria. These components create an environment that is favorable for the growth of coliform bacteria while inhibiting the growth of other microorganisms.
The lactose component of BGLB allows for the differentiation of coliform bacteria from other members of the enterobacteriaceae group. Coliform bacteria possess enzymes that can ferment lactose, producing acid and gas as byproducts. The acid production results in a color change in the medium, indicating the presence of coliform bacteria. Non-coliform bacteria, on the other hand, do not possess these enzymes and are unable to ferment lactose, resulting in no color change.
**2. Testing for the presence of bacteria, including E. coli and others, in the ocean and assigning a grade to beaches based on the results is important for several reasons. First, bacteria in recreational waters can pose a health risk to swimmers and beachgoers. Certain bacteria, such as E. coli, can indicate the presence of fecal contamination and the potential presence of pathogens that can cause illnesses.
Assigning a grade to beaches based on bacterial contamination levels helps inform the public about the safety of the water and allows individuals to make informed decisions regarding swimming and other recreational activities. It also encourages beach managers and local authorities to take appropriate actions to address water quality issues and ensure the protection of public health.
**3. Coliforms are a group of bacteria that share certain characteristics and are commonly used as indicators of water quality and sanitation. Some key characteristics of coliform bacteria include:
- - They are gram-negative, rod-shaped bacteria.
- - They are facultative anaerobes, meaning they can grow in the presence or absence of oxygen.
- - They are non-spore forming.
- - They ferment lactose with the production of acid and gas.
- - They are widely distributed in nature, including in the intestines of humans and other warm-blooded animals.
- - The presence of coliforms in water or food samples is often used as an indicator of fecal contamination and the potential presence of other harmful bacteria.
**4. If the lab technician mistakenly added glucose instead of lactose in the medium, the results and interpretation would differ. Glucose is not a differentiating factor for coliform bacteria, so the medium would not be able to differentiate coliforms from other members of the enterobacteriaceae group. Without the ability to differentiate, it would be challenging to determine the presence of coliform bacteria accurately.